package br.com.biblioteca.controller;

import br.com.biblioteca.exceptions.BadRequestException;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.lang.StringUtils;

/**
 *
 * @author joaosavio
 */
public class FrontController extends HttpServlet {
    private static final String PACKAGE = "br.com.biblioteca.controller";
    private static final String DOT = ".";

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String action = request.getParameter(Page.ACTION_PARAMETER);
        System.out.println(action);
        if (StringUtils.isEmpty(action)) {
            throw new BadRequestException("Action mismatch");
        }
        String name = request.getParameter(Page.SERVICE_PARAMETER);
        String serviceClassName = PACKAGE + DOT + name;
        Class serviceClass;
        try {
            serviceClass = Class.forName(serviceClassName);
        } catch (ClassNotFoundException e) {
            throw new ServletException(serviceClassName + " not found");
        }
        if (!IService.class.isAssignableFrom(serviceClass)) {
            throw new ServletException(serviceClassName + " not implement IBusinessClass");
        }
        IService service;
        try {
            service = (IService) serviceClass.newInstance();
            ServiceRequestTO serviceRequestTO = new ServiceRequestTO(request, response, action);
            service.execute(serviceRequestTO);
        } catch (Exception e) {
            throw new ServletException(e);
        }
    }

 
    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** 
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>


}
